diff --git a/libs/apexutil/TEST_MAPPING b/libs/apexutil/TEST_MAPPING
index f66a400..73848d3 100644
--- a/libs/apexutil/TEST_MAPPING
+++ b/libs/apexutil/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {
diff --git a/libs/apkverify/TEST_MAPPING b/libs/apkverify/TEST_MAPPING
index 7224fc7..6bbc624 100644
--- a/libs/apkverify/TEST_MAPPING
+++ b/libs/apkverify/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {
diff --git a/libs/avb/TEST_MAPPING b/libs/avb/TEST_MAPPING
index 2f4bccc..57de6b3 100644
--- a/libs/avb/TEST_MAPPING
+++ b/libs/avb/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {
diff --git a/libs/capabilities/TEST_MAPPING b/libs/capabilities/TEST_MAPPING
index 568a771..902c6e5 100644
--- a/libs/capabilities/TEST_MAPPING
+++ b/libs/capabilities/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {
diff --git a/libs/devicemapper/TEST_MAPPING b/libs/devicemapper/TEST_MAPPING
index 23d10c4..cbe7442 100644
--- a/libs/devicemapper/TEST_MAPPING
+++ b/libs/devicemapper/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {
diff --git a/libs/fdtpci/TEST_MAPPING b/libs/fdtpci/TEST_MAPPING
index c315b4a..192a7c6 100644
--- a/libs/fdtpci/TEST_MAPPING
+++ b/libs/fdtpci/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit": [
     {
diff --git a/libs/libfdt/TEST_MAPPING b/libs/libfdt/TEST_MAPPING
index 596f84b..e2f8dbb 100644
--- a/libs/libfdt/TEST_MAPPING
+++ b/libs/libfdt/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit": [
     {
diff --git a/libs/vbmeta/TEST_MAPPING b/libs/vbmeta/TEST_MAPPING
index e42aea0..92016c7 100644
--- a/libs/vbmeta/TEST_MAPPING
+++ b/libs/vbmeta/TEST_MAPPING
@@ -1,3 +1,5 @@
+// When adding or removing tests here, don't forget to amend _all_modules list in
+// wireless/android/busytown/ath_config/configs/prod/avf/tests.gcl
 {
   "avf-presubmit" : [
     {